Malicious PDF — malware analysis report

Static analysis result for SHA-256 4261ff9e6281fd81…

MALICIOUS

PDF

70.4 KB Created: 2021-10-02 12:37:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: da7e133279b9ba4cdeb469b43eebb9f4 SHA-1: d91e120b5bf7c373792f8e852c38447905733f28 SHA-256: 4261ff9e6281fd813c7f792deea5236663c943bc14c60a7007a368eab355b8d3
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains embedded JavaScript and numerous external URIs pointing to disposable hosting, indicative of a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. The embedded JavaScript is likely used to facilitate the redirection or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://catamma.ru/uplcv?utm_term=foundations+of+educational+theory+for+online+learning PDF link annotation
    • https://hv2barrier.com/application/third_party/ckfinder/userfiles/files/7432712146.pdfIn PDF document text
    • http://nail-free.com/ckfinder/userfiles/files/38152142360.pdfIn PDF document text
    • http://ecoaga.com/documentos/file/76405479636.pdfIn PDF document text
    • https://westhygiene.hu/editor_up/defudazajakesaziduzexa.pdfIn PDF document text
    • http://nuk-amro.de/userfiles/file/86621007479.pdfIn PDF document text
    • https://palezieux.com/ckfinder/userfiles/files/62253572349.pdfIn PDF document text
    • http://teen.plovdivweek.com/js/ckfinder/userfiles/files/59807228127.pdfIn PDF document text
    • http://flightshop.jp/images/blog/file/fivin.pdfIn PDF document text
    • http://www.stockholmswingallstars.com/wp-content/plugins/formcraft/file-upload/server/content/files/161492224723e1---bofimeganufoxo.pdfIn PDF document text
    • http://tythb.cn/uploadfile/files/bemepapujajanenixi.pdfIn PDF document text
    • http://aaronandanthony.com/userfiles/files/wijitabegiropuxofu.pdfIn PDF document text
    • http://bakineshr.az/ckfinder/userfiles/files/51619703728.pdfIn PDF document text
    • https://libyamonitor.com/sites/all/libraries/ckfinder/userfiles/files/59509797149.pdfIn PDF document text
    • http://metamorfozyayincilik.com/userfiles/file/98762184916.pdfIn PDF document text
    • http://toonesk.com/upload/kobelajulebavezelopegesid.pdfIn PDF document text
    • http://avandcie-energy.fr/ckfinder/userfiles/files/lolosejorivirefekir.pdfIn PDF document text
    • https://bi-kiesabbau.de/cmsimple/images/file/devuzizuvozisu.pdfIn PDF document text
    • https://playgametoday.ru/wp-content/plugins/super-forms/uploads/php/files/3c47a96bfb50e44f07eefa055e560fa3/lulufewisotadawati.pdfIn PDF document text
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/1613da533ba6f2---dulidawavosez.pdfIn PDF document text
    • http://reklama-kemerovo.ru/files/files/74152850568.pdfIn PDF document text
    • http://mayinmaunhat.com/upload/files/jujinukurifapolenasatu.pdfIn PDF document text
    • https://electroagro.es/pub/files/4692946440.pdfIn PDF document text
    • http://hoteldarim.ir/basefile/hoteldarimir/files/kazawonumopevigipibivira.pdfIn PDF document text
    • http://retroldn.com/userfiles/file/93900190705.pdfIn PDF document text
    • http://suncitygroup.ir/basefile/suncitygroupir/files/mitawa.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b3fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB3FD 15168 bytes
SHA-256: f4fa719e294c4df2c01545284adf624867c7c72924fddf152ff0a6a17e8379b3
font_01_sfnt_off0000da3d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA3D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f254.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF254 10944 bytes
SHA-256: 2a5c959e5360df34929232ac18ac78c1a376862f17cb594bb0dd960fba8bbdc4